The SNMR signal is disturbed usually by the spike noise because of the extremely weak signal with nV grade, the signal SNR is low and the error value of SNMR signal parameters is big.

• 地面核磁共振信号是纳伏级的微弱信号，实际测量中易受到奇异噪声干扰，导致信号信噪比低，信号参数提取误差大。